This invention relates generally to sealing corked bottles and, more particularly, to automated methods and apparatus for forming embossed seals on corked bottles having high-quality embossed images at a commercially desirable process rate.
One of the methods of sealing corked bottles involves the use of thermoplastic seals. A thermoplastic material is typically injected in liquefied form into the mouth of the neck of a corked bottle and placed on top of the cork wherein it hardens and forms a seal with the interior surface of the bottle neck and the cork. Thermoplastic seals are generally preferred over lead-containing metal foils and more aesthetically pleasing than plastic seals. Thermoplastic seals that include an aesthetic finish of an embossed design or logo on the exposed top surface are often desirable. Embossed thermoplastic seals can also be tamper-evident.
Finishing or embossing a thermoplastic seal on a corked bottle presents production problems. The time it takes for the liquefied thermoplastic material to harden can severely impact production speed. If the liquefied thermoplastic material is not allowed to harden sufficiently, the residual heat may melt part or all of the hardened finish and ruin the embossing. In addition, the embossing step requires precise control to ensure that the embossing is uniform for each seal. Uniformity must be achieved without sacrificing production speed.
The present invention is directed to an apparatus and method for forming embossed seals on corked bottles at a process rate that is economically desirable while achieving uniformity and avoiding residual heat problems. This is accomplished by forming the seal in two stages. First, an upper seal portion is formed by introducing molten seal material into a die cavity formed using a die having a die surface with a die image of a logo or design. The upper seal portion is allowed to cool sufficiently so that the region around the embossed image is solidified. Molten seal material is separately introduced into the cavity above the cork in the bottle neck. In the second stage, the cooled upper seal portion is brought into contact with the molten seal material in the bottle neck cavity with the embossed image disposed on top facing away from the molten seal material. The bottom region of the upper seal portion is partially melted and joined with the molten seal material to form a single seal over the corked bottle upon cooling. The upper seal portion is adequately cooled and solidified so that the embossed image is not melted or otherwise damaged during the partial melting by and joining with the molten seal material at the bottom. In a preferred embodiment, this process is automated and is sufficiently fast and repeatable to produce high quality embossed seals for sealing corked bottles.
An aspect of the present invention is directed to a method of forming an embossed seal in a cavity in the neck of a corked bottle over a cork using a die having a die surface with a die image. The method includes bringing the die surface in contact with a first molten seal material and cooling the molten seal material to form an embossed seal portion with an embossed surface on one side and an interface surface on another side. A second molten seal material is introduced into the cavity of the neck of the corked bottle over the cork. The interface surface of the cooled embossed seal portion is brought into contact with the molten seal material in the cavity to partially melt the embossed seal portion and join the embossed seal portion with the molten seal material in the cavity to form a seal having the embossed surface over the cork. The amount of the first molten seal material typically includes about 50% to about 90% of the sum of the amount of the first molten seal material and the amount of the second molten seal material. In a specific embodiment, the amount of the first molten seal material is about 80% of the sum of the first and second molten seal material. In a preferred embodiment, the contact between the die surface and the embossed seal portion is maintained until the molten seal material in the cavity is at least partially solidified.
In some embodiments, a gas flow is directed toward the first molten material to distribute the first molten material to form a desired interface surface profile. For example, the interface surface profile formed may be generally planar, or generally concave with a raised edge around a depressed center. A gas flow may be directed toward the second molten material to distribute the second molten material to form a desired surface profile, which may be, for instance, generally planar or generally concave.
In accordance with another aspect of the invention, a die truck assembly for forming the first seal portion includes an actuator guide block and a die holder coupled with the actuator guide block by an actuator spring. The die holder is movable relative to the actuator guide block between a rest position and a compressed position. The actuator spring is compressed in the compressed position to bias the die holder toward the rest position. The die holder includes a die stem having a die support portion and a spring seat. A centering member is coupled with the spring seat by an engagement spring and is movable relative to the spring seat between a rest position and a compressed position. The engagement spring is compressed in the compressed position to bias the centering member toward the rest position.
In preferred embodiments, the die holder further includes a blocking member which is generally fixed on the die stem. The blocking member is coupled with the spring seat by a die stem spring and is movable relative to the spring seat between a rest position and a compressed position. The die stem spring is compressed in the compressed position to bias the blocking member toward the rest position. In a specific embodiment, the die holder includes an actuator guide tube and the actuator spring is coupled between the actuator guide tube and the actuator guide block. The spring seat is generally fixed on the actuator guide tube, and the die stem is slidable relative to the actuator guide tube. A die is supported by the die support portion, and includes a die surface with a die image. The centering member includes an inner wall which is disposed around the die. The die is recessed from the edge of the inner wall in the rest position of the engagement spring to form a die cavity with the inner wall. When the engagement spring is compressed in the compressed position, the die protrudes from the edge of the inner wall to release the first seal portion from the assembly.
The actuator spring, engagement spring, and die stem spring provide a triple telescoping action of the die truck assembly that (1) allows it to be engaged with the bottle neck and maintains the engagement along a specific travel path to form a seal to seal the bottle; (2) releases the embossed seal portion from the die cavity of the die truck assembly into the molten seal material in the cavity over the cork in the bottle neck; and (3) allows the die truck assembly easily to self-adjust and compensate for varying bottle heights and varying cork heights so as to exert a generally consistent pressure on the embossed seal portion and molten seal material to form the finished seal.
In accordance with another aspect of the invention, a die truck assembly comprises a die holder including a die stem having a die support portion and a spring seat. The die holder includes a blocking member which is generally fixed on the die stem. The blocking member is coupled with the spring seat by a die stem spring and is movable relative to the spring seat between a rest position and a compressed position. The die stem spring is compressed in the compressed position to bias the blocking member toward the rest position. A centering member is coupled with the spring seat by an engagement spring and is movable relative to the spring seat between a rest position and a compressed position. The engagement spring is compressed in the compressed position to bias the centering member toward the rest position.
The engagement spring and die stem spring provide a double telescoping action of the die truck assembly that releases the embossed seal portion from the die cavity of the die truck assembly into the molten seal material in the cavity over the cork in the bottle neck, and allows the die truck assembly easily to self-adjust and compensate for varying bottle heights and varying cork heights so as to exert a generally consistent pressure on the embossed seal portion and molten seal material to form the finished seal. In this embodiment, the bottle is typically moved toward the die truck assembly to engage the bottle neck with the assembly.
In accordance with another aspect of the present invention, an apparatus for forming embossed seals in cavities in the necks of corked bottles includes a main support frame and an endless drive chain mounted on the main support frame. A plurality of die truck assemblies are spaced along and coupled with the endless drive chain. Each die truck assembly includes a die cavity. A first applicator is provided for introducing a first molten seal material into the die cavity of each die truck assembly to form a first seal portion therein. A second applicator is provided for introducing a second molten seal material into the cavity of the neck of each corked bottle. The apparatus further includes a bottle conveyor for conveying the bottles to generally align the neck of each bottle with one of the plurality of die truck assemblies over a portion of travel of the conveyor. A release mechanism is provided for releasing the first seal portion from each die truck assembly into the second molten seal material in the cavity of the neck of one of the corked bottles.
In some embodiments, at least one nozzle is provided for directing a gas flow toward the first molten seal material in the die cavity to distribute the first molten seal material and form the first seal portion therein with a desired interface surface profile. The nozzle may be coupled to a cooling gas source to direct a cooling gas flow toward the first molten seal material to cool the first molten seal material. The nozzle may be configured to direct the gas flow toward the central region of the first molten seal material to spread the first molten seal material from the central region to the edge region thereof.
In some embodiments, at least one nozzle is provided for directing a gas flow toward the second molten seal material in the cavity of the neck of each corked bottle to distribute the second molten seal material and form the second seal portion therein with a desired surface profile. The nozzle may be coupled to a cooling gas source to direct a cooling gas flow toward the second molten seal material to cool the second molten seal material.
In preferred embodiments, a first reciprocator is coupled with the first applicator for cyclically moving the first applicator to follow the movement of each die truck assembly between a first position and a second position to provide additional deposition time for the first molten seal material. A second reciprocator is coupled with the second applicator for cyclically moving the second applicator to follow the movement of each bottle between a first position and a second position to provide additional deposition time for the second molten seal material. A bottle guide in the form of a timing screw is provided for guiding the bottles onto the bottle conveyor at a speed and a spacing between adjacent bottles to generally align the neck of each bottle with one of the die truck assemblies driven by the drive chain.
In a specific embodiment, a single variable-speed drive motor is provided for driving a drive sprocket coupled with the drive chain, the first reciprocator, the second reciprocator, and the timing screw. The connections between the drive motor and these components preferably synchronize the movements of the components for introducing the first molten seal material into the die cavity of each die truck assembly, introducing the second molten seal material into the cavity in each bottle neck, and aligning each die truck assembly with the corresponding bottle to form the finished seal by joining the upper and lower seal portions inside the cavity of the bottle. The synchronism in the specific embodiment is achieved by mechanical connections. By adjusting the speed of the drive motor, the process rate of the apparatus can be easily changed while preserving the synchronized movement of the various components.
In a preferred embodiment, the drive motor, drive sprocket and drive chain, first reciprocator, and second reciprocator are attached to the main support frame, while the timing screw is attached to a lower support frame. The main support frame is adjustable in position relative to the lower support frame when necessary to adapt the apparatus for processing bottles of a different height. The attachment of these components to the upper and lower support frames, respectively, and easy adjustment of the upper support frame relative to the lower support frame simplifies the process of adapting the apparatus to different bottle heights.